The present invention relates to an Electronic Power Conditioner (EPC) for Solid State Power Amplifier (SSPA) and more particularly to a high efficiency main stage converter based on a Full-Bridge input switch with an integrated magnetic structure and Hy-bridge rectification using synchronous rectifiers.
On commercial telecommunication satellites using Phased Array Antennas (PAA), up to 70% of available payload power is handled by a DC/DC converters supplying a Solid State Power Amplifier (SSPA) for each antenna element.
In the recent decades, the satellite communication business segment has experienced vigorous growth. This growth is best exemplified by development in the last decade of satellite fleets. Table 1 illustrates growth of Inmarsat, currently one of the biggest operators of satellites.
TABLE 1Inmarsat 2Inmarsat 3Inmarsat 4Satellites in orbit452 + 1 spareMass at launch [kg]120020705950Launched1990-19921996-1998Q1-Q2 2005PAA elements133150Mobil Link * EIRP [dBW]394867Bandwidth [kbps]0.6Up to 64432Platform power [W]1200230012000Payload power [W]Unknown16009000
The growth in the mass of the satellites at launch and the number of satellites in orbit has been driven by an increased need for a transmission signal bandwidth, transmitted signal strength, and transmission coverage on the ground. As indicated in Table 1, the rapid increase in “strength” of the communication payload has been accompanied by an increasing need for power.
For example, for the Inmarsat 4 satellites the Electronic Power Conditioner EPC for SSPA handles 75% of the payload power and 55% of the total power available from the platform. This makes the EPC and the SSPA the single most important payload component for the satellites' power budget. As a natural consequence, efficiency becomes the most important performance parameter for the EPC for SSPA.
The second most important performance parameter is mass. This parameter is driven by penalties charged in the space programs for extra mass. The penalties reflect the cost of lifting and operating the mass in space. The mass penalty for a large Geostationary Earth Orbiting (GEO) communication satellites normally equals 60 $/g. For Inmarsat 4 satellites, which have 150 EPCs for SSPA, this equals a 9000 $/g mass penalty for each of the three delivered satellites.
However, as the overall mass of the 150 EPCs equals approximately 40 kg or less than 1% of the overall mass of the satellite this parameters is not surrounded with the same amount of concern as the efficiency. Thus, the two key parameters for an EPC for SSPA are efficiency followed by mass.